Resolve "Add fOERde"

Related to #149 @fsteeg I receive an error for:

2022-07-04 15:32:26 [ERROR] [ETL:105] Error processing import channel foerde-to-oersi.flux
org.metafacture.metafix.FixExecutionException: Error while executing Fix expression (at file:/home/tobias/git/oersi-etl/data/production/foerde/foerde_edu-sharing.fix, line 139): lookup("@learningResourceType[].*","data/maps/foerdeLeardningResourceTypes.tsv","sep_char":"\t")
        at org.metafacture.metafix.RecordTransformer.tryRun(RecordTransformer.java:202)
        at org.metafacture.metafix.RecordTransformer.lambda$transform$2(RecordTransformer.java:95)
        at java.base/java.lang.Iterable.forEach(Iterable.java:75)
        at org.metafacture.metafix.RecordTransformer.transform(RecordTransformer.java:94)
        at org.metafacture.metafix.Metafix.endRecord(Metafix.java:191)
        at org.metafacture.json.JsonDecoder.decode(JsonDecoder.java:194)
        at org.metafacture.json.JsonDecoder.processRecord(JsonDecoder.java:147)
        at org.metafacture.json.JsonDecoder.process(JsonDecoder.java:136)
        at org.metafacture.json.JsonDecoder.process(JsonDecoder.java:44)
        at org.metafacture.io.LineReader.process(LineReader.java:56)
        at org.metafacture.io.LineReader.process(LineReader.java:48)
        at org.metafacture.io.LineReader.process(LineReader.java:36)
        at org.metafacture.io.HttpOpener.process(HttpOpener.java:100)
        at org.metafacture.io.HttpOpener.process(HttpOpener.java:41)
        at oersi.SitemapReader.process(SitemapReader.java:59)
        at oersi.SitemapReader.process(SitemapReader.java:23)
        at org.metafacture.flux.parser.StringSender.process(StringSender.java:38)
        at org.metafacture.flux.parser.Flow.start(Flow.java:110)
        at org.metafacture.flux.parser.FluxProgramm.start(FluxProgramm.java:156)
        at org.metafacture.runner.Flux.main(Flux.java:79)
        at oersi.ETL.run(ETL.java:101)
        at oersi.ETL.main(ETL.java:55)
Caused by: java.lang.IllegalStateException: Expected Array or Hash, got String
        at org.metafacture.metafix.Value$TypeMatcher.lambda$orElseThrow$0(Value.java:332)
        at org.metafacture.metafix.Value$TypeMatcher.orElse(Value.java:325)
        at org.metafacture.metafix.Value$TypeMatcher.orElseThrow(Value.java:330)
        at org.metafacture.metafix.FixPath.lambda$findIn$2(FixPath.java:62)
        at org.metafacture.metafix.Value.extractType(Value.java:245)
        at org.metafacture.metafix.FixPath.findIn(FixPath.java:59)
        at org.metafacture.metafix.Record.transform(Record.java:201)
        at org.metafacture.metafix.FixMethod$31.apply(FixMethod.java:381)
        at org.metafacture.metafix.RecordTransformer.lambda$null$15(RecordTransformer.java:166)
        at org.metafacture.metafix.RecordTransformer.lambda$null$17(RecordTransformer.java:182)
        at org.metafacture.metafix.RecordTransformer.lambda$null$1(RecordTransformer.java:95)
        at org.metafacture.metafix.RecordTransformer.tryRun(RecordTransformer.java:193)
        ... 21 more
2022-07-04 15:32:26 [INFO] [ETL:106] Import channel foerde-to-oersi.flux FAILED: Error while executing Fix expression (at file:/home/tobias/git/oersi-etl/data/production/foerde/foerde_edu-sharing.fix, line 139): lookup("@learningResourceType[].*","data/maps/foerdeLeardningResourceTypes.tsv","sep_char":"\t") (IllegalStateException)

I do not understand why the function expects an hash or an array?